The present invention relates generally to tone generation apparatus and methods for generating musical tones, voices or other desired sounds. More particularly, the present invention relates to an improved tone generation apparatus and method capable of generating tone waveforms, rich in expression, by controlling various envelopes of waveform data in correspondence with styles of rendition. Note that the present invention is applicable extensively to various equipment, apparatus and methods of all fields capable of producing waveforms of musical tones, voices or other desired sounds, such as automatic performance apparatus, computers, electronic game apparatus and other types of multimedia equipment, not to mention ordinary electronic musical instruments. It should also be appreciated that in this specification, the terms xe2x80x9ctone waveformxe2x80x9d are used to refer to not only a waveform of a musical tone but also a waveform of a voice or other sound.
The so-called xe2x80x9cwaveform memory readoutxe2x80x9d method has been well known, in which waveform data of one or more cycles, encoded by a desired encoding technique, such as the PCM (Pulse Code Modulation), DPCM (Differential PCM) or ADPCM (Adaptive Differential PCM), are prestored in a waveform memory so that a suitable tone waveform can be produced by repetitively reading out the stored waveform data from the memory at a rate corresponding to a desired tone pitch. There have been known various types of waveform memory readout techniques. In tone generators employing such a waveform memory readout technique, it has been conventional to not only merely output waveform data, read out from the waveform data memory, as tone waveform signals, but also control the read-out waveform data for each of predetermined tone factors, such as a tone pitch, volume and color (timbre), so as to produce a tone waveform rich in expression. Among examples of waveform control for controlling a waveform in such a tone generator is the one that is based on various envelope generators (EG), such as a pitch envelope generator, amplitude envelope generator and filter envelope generator, contained in the tone generator. The pitch envelope generator controls a pitch envelope of a tone to be generated so that a readout rate of waveform data is varied in accordance with the controlled pitch envelope to thereby produce a tone waveform of a time-varying pitch. The amplitude envelope generator forms or produces a tone volume envelope and imparts the thus-produced tone volume envelope to waveform data read out from the waveform data memory to thereby control the volume from the beginning to end of sounding of the corresponding tone. Further, the filter envelope generator controls tone color controlling filter characteristics so that waveform data, read out from the waveform data memory, are processed with a filter having the controlled characteristics to produce a tone waveform of a time-varying pitch.
As another example of the waveform control for controlling a waveform, there has hitherto been known the xe2x80x9ccontinuous waveform controlxe2x80x9d, by which a user can control a tone pitch, tone volume, tone color or the like to vary continuously by manipulating a predetermined operator (e.g., expression pedal, bend wheel or modulation wheel) or the like at a given time during a music piece performance whenever the user wants to vary intonation in the performance such as expression, pitch bend, modulation depth, modulation speed or the like. Various control values having been set by the continuous control can be stored in a sequencer, and the thus-stored control values can be edited, as necessary, in the sequencer.
Also known is the waveform control based on a style-of-rendition template function that is provided by a sequencer as its unique function. This waveform control, in response to designation of a musical symbol, imparts music piece data with macro pattern data (or style-of-rendition template) prepared beforehand in association with the designated musical symbol, to thereby control a tone pitch, tone volume, tone color or the like. Among musical symbols and signs for which style-of-rendition templates are prepared beforehand are: dynamic marks like crescendo, diminuendo, piano and mezzo forte; cadence marks like fermata; tempo marks like accelerando and ritardando; and performance indications like glissando, portamento, choking, tremolo, staccato and accent. Still another example of the waveform control has been proposed by the assignee of the instant application in Japanese Patent Laid-open Publication No. 60-60693, in accordance with which a plurality of pitch modulating waveforms (e.g., those of attack pitch, vibrato, portamento and the like), each covering an entire sounding period from the rise to fall of a tone, are prestored in memory and only ones of the pitch modulating waveforms, currently selected by turning on selection switches or otherwise, are combined so as to vary the pitch of the tone on the basis of the resultant synthesized pitch modulating waveform.
However, the above-discussed conventional waveform control techniques for producing a tone waveform would present problems in the following respects. Namely, the above-discussed waveform control technique based on various envelope generators, which is designed to normally perform waveform control per tone such as waveform control of the rise or fall portion of the tone, can not appropriately control a gentle variation etc. of a waveform per phrase (e.g., per measure). With the above-discussed continuous waveform control which is performed independently of individual notes to be performed, it is difficult to control a waveform of only a particular performance section, such as an attack portion, of a tone, a waveform of only a particular tone or phrase, etc. Further, the waveform control based on a style-of-rendition template function of a sequencer can not be used to vary expression of each desired performance section and hence lacks flexibility, because all the style-of-rendition templates have a same time length, i.e. because this waveform control technique is not designed to synthesize a variation curve using a plurality of style-of-rendition templates hierarchically organized according to different time lengths. Further, because the style-of-rendition templates are intended for continuous waveform control, when control is to be performed on a voice (tone color waveform) made up of a plurality of elements, it is not possible to impart a unique style of rendition to each of the elements. Furthermore, the above-mentioned waveform control based on a pitch modulating waveform covering an entire sounding period, where each of the pitch modulating waveforms capable of being turned on and off is intended to control a waveform of an entire tone from the rise to fall thereof, can not control a waveform of only an attack portion of a tone, a waveform of a particular phrase, or the like.
Therefore, for most of the known tone generators employing the conventional waveform control, it has been extremely difficult to perform waveform control to permit great many variations per predetermined portion of a tone or to permit desired variations across a plurality of tones.
In view of the foregoing, it is an object of the present invention to provide an improved tone generation apparatus and method which can generate tones while readily performing waveform control on a portion of one or more tones in addition to tone-by-tone waveform control.
For example, the present invention seeks to provide a tone generation apparatus and method which can readily perform waveform control on a particular performance section of a tone, by synthesizing an envelope appropriately using a template representative of a characteristic variation curve to be imparted to the performance section of the tone and producing a tone waveform in accordance with the thus-synthesized envelope. The present invention also seeks to provide a tone generation apparatus and method which can readily perform fine waveform control on a particular performance section of a phrase or tone by preparing beforehand templates, each representative of a characteristic variation curve to be imparted to a performance section of a phrase or tone, for each of different time lengths, such as those of phrases, notes, attack portions and release portions, synthesizing an envelope by appropriately combining selected ones of the templates of different time lengths and producing a tone waveform in accordance with the thus-synthesized envelope. The present invention also seeks to provide a tone generation apparatus and method which can modify a shape of a characteristic variation curve of each template, selected from among a plurality of templates each representative of a characteristic variation curve to be imparted to a performance section of a phrase or tone, in accordance with a level, time length or the like of the characteristic variation curve, and thereby allows a user to produce a tone waveform while controlling the tone waveform for each desired performance section.
According to an aspect of the present invention, the present invention provides a tone generation apparatus which comprises: a performance information supply section that supplies performance information; a segment template supply section that supplies a segment template including a partial characteristic variation curve and position information; an envelope synthesis section that produces a basic envelope for at least one tone on the basis of the performance information, arranges, on a time axis based on the performance information, the characteristic variation curve of the segment template in accordance with the position information and combines the characteristic variation curve, arranged on the time axis, with the basic envelope, to thereby produce a synthesized envelope for the at least one tone; and a tone generation section that generates a tone using the produced synthesized envelope.
According to the present invention, the partial characteristic variation curve of a desired segment template is combined with a basic envelope of at least one tone produced on the basis of supplied performance information in arrangement corresponding to the position information included in the segment template, so that a synthesized envelope is produced. Thus, by use of the segment template alone, the present invention can readily produce a synthesized envelope that permits fine control of a particular performance section of a tone. As a result, the present invention can easily produce a tone waveform rich in expression and corresponding to a style of rendition, using the synthesized envelope; namely, the user of the inventive tone generation apparatus can readily generate a tone presenting complicated variations, using a desired segment template.
According to another aspect of the present invention, there is provided a tone generation apparatus which comprises: a performance information supply section that supplies performance information; a segment template supply section that is capable of supplying a plurality of segment templates of different lengths, each of the segment templates including a characteristic variation curve; an envelope synthesis section that arranges the characteristic variation curves of two or more segment templates of different lengths, in correspondence with a given performance section based on the performance information, in such a manner that at least parts of the characteristic variation curves of the two or more segment templates overlap with each other, and produces a synthesized envelope for the given performance section by combining the arranged characteristic variation curves; and a tone generation section that generates a tone using the produced synthesized envelope.
According to the present invention, the characteristic variation curves of two or more segment templates of different lengths are arranged in such a manner that at least respective parts of the characteristic variation curves of the two or more segment templates overlap with each other and a synthesized envelope is produced on the basis of the combination of the characteristic variation curves. Thus, when, for example, fine envelope control is to be performed in a given part of a performance section, it suffices to just paste a characteristic variation curve corresponding to a fine envelope of a necessary length. Namely, the present invention can readily perform fine envelope control of a partial performance section by just combining appropriate segment templates of different time lengths.
According to still another aspect of the present invention, there is provided a tone generation apparatus which comprises: a performance information supply section that supplies performance information; a segment template supply section that is capable of supplying segment templates each including a characteristic variation curve, the segment templates including note segment templates corresponding to substantial total lengths of tones and tone-portion segment templates corresponding to lengths of tone portions; an envelope synthesis section that, in correspondence with a given performance section of a tone based on the performance information, selects one note segment template and one or more tone-portion segment templates, places the selected note segment templates in the given performance section of the tone and the selected tone-portion segment templates in a part of the given performance section of the tone, and produces a synthesized envelope for the given performance section by combining respective characteristic variation curves of the placed segment templates; and a tone generation section that generates a tone using the produced synthesized envelope. In this case too, the present invention can readily perform fine envelope control of a part of a partial performance section of a tone.
According to still another aspect of the present invention, there is provided a tone generation apparatus which comprises: a performance information supply section that supplies performance information; a segment template supply section that supplies a segment template representative of a characteristic variation curve; a modification section that arranges the segment template on a time axis based on performance timing specified by the performance information and modifies the characteristic variation curve of the arranged segment template; an envelope synthesis section that produces a basic envelope on the basis of the performance information and combines the characteristic variation curve, modified by the modification section, with the basic envelope, to thereby produce a synthesized envelope; and a tone generation section that generates a tone using the produced synthesized envelope. By modifying the characteristic variation curve, the present invention can perform fine envelope control rich in variations.
The present invention may be constructed and implemented not only as the apparatus invention as discussed above but also as a method invention. Also, the present invention may be arranged and implemented as a software program for execution by a processor such as a computer or DSP, as well as a storage medium storing such a program. Further, the processor used in the present invention may comprise a dedicated processor with dedicated logic built in hardware, not to mention a computer or other general-purpose type processor capable of running a desired software program.
While the embodiments to be described herein represent the preferred form of the present invention, it is to be understood that various modifications will occur to those skilled in the art without departing from the spirit of the invention. The scope of the present invention is therefore to be determined solely by the appended claims.